# CVE-2009-2936: Missing authorization in n/a

> Remote attackers can execute arbitrary code, escalate privileges, or read files via the unauthenticated Varnish CLI interface.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Apr 2010
- **Updated:** 7 Aug 2024
- **Also known as:** DEBIAN-CVE-2009-2936, GHSA-vq42-25hh-c536

## What is CVE-2009-2936?

CVE-2009-2936 is a high-severity missing authorization vulnerability in n/a, published on 5 Apr 2010. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Command Line Interface (aka Server CLI or administration interface) in the master process in the reverse proxy server in Varnish before 2.1.0 does not require authentication for commands received through a TCP port, which allows remote attackers to (1) execute arbitrary code via a vcl.inline directive that provides a VCL configuration file containing inline C code; (2) change the ownership of the master process via param.set, stop, and start directives; (3) read the initial line of an arbitrary file via a vcl.load directive; or (4) conduct cross-site request forgery (CSRF) attacks that leverage a victim's location on a trusted network and improper input validation of directives.  NOTE: the vendor disputes this report, saying that it is "fundamentally misguided and pointless.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2009-2936?

It affects 1 product.


Products: Varnish.projects.linpro Varnish.

## How do I fix CVE-2009-2936?

Upgrade to a fixed version.

## Is CVE-2009-2936 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-2936 exists.

Public exploit code:

- Varnish Cache CLI Interface - Remote Code Execution (Metasploit) (exploitdb)
- Varnish Cache CLI File Read (metasploit)
- Varnish Cache CLI Login Utility (metasploit)

## Other vulnerabilities in n/a

- [CVE-2009-4488](https://insights.sbomify.com/CVE-2009-4488/): Other in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-2936 and fix it if it is affected.

What it is: CVE-2009-2936 is a high-severity missing authorization vulnerability in n/a, published on 5 Apr 2010. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2009-2936 exists.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2009-2936/ (Markdown: https://insights.sbomify.com/CVE-2009-2936/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-2936
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-2936
- OSV: https://osv.dev/vulnerability/CVE-2009-2936

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-2936/
Summaries are generated and may contain mistakes; the official description above is the record.